James a



(No Model.)

J. A. MALONEY.

PNBUMATIG AGOUSTIG TELEPHONE. No. 338,994. Patented Mar. 30, 1886.

mmuuluulullmumr AT'I'ORNE S UNITED STATES PATENT OFFICE.

JAMES A. MALONEY, OF WASHINGTON, DISTRIOT OF OOLUMBIA, ASSIGNOR OF ONE-HALF TO HENRY D. OOOKE, OF SAME PLAOE.

PNEUMATIC ACOUSTIC TELEPHON E.

.,rlCIFICATION forming part of Letters Patent No. 338,994, dated March 30, 1886.

Applicationfiled July 2, 1885. Serial No. 170,505. (No model.)

To all whom it may 'concern- Be it known that I, J AMns A. MALONEY, a citizen of the United States, residing at Vashington, in the District of Columbia, have invented certain new and useful Improvements in Pneumatic Acoustic Telephones; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to whichit io appertains to made and use the same.

My invention relates to apneumatic acoustic telephone; and has for its object the construction of an instrument for conveying articulate or other sounds through tubes to a'greater or less distance, so as to render them audible at extremities thereof.

"Heretofore sounds'have been conveyed through tubes containing confined air and fluids under pressure. At each end of the tube a fiXed diaphragm has been located in a receiver or transmitter, and in each case the confined fluid has been made the medium of transmitting the sound -waves,.produced by the human voice, being directed against the diaphragm from one end of the line to the other. These devices have been defective,in th at great exertion is required on the part of the person desiring to transmit a message, as only loud '30 sounds produced at one end of the line are rendered audible at the other, due to the loss incurred by the fixed diaphragm and the thus limited amount of its vibration,which proves a great annoyance to the person using the instrument and to others around it, and precludes the possibility of speaking to a person at a distance withouthaving the conversation heard by others in the room from which the message is being transmitted. Extensive eX- 40 periments in this line of invention have led me to the discovery that a diaphragm free to vibrate at its periphery is far more Sensitive to the effects produced by the sound-Waves striking it upon either side, than a diaphragm fixed at its periphery and vibrating only between its rigid boundaries, and makes it practicable to transmit messages given in whisper tones and render them audible at a great distance.

My invention consists in the construction hereinafter described, and particularly pointed out in the claims.

Reference being had to the accompanying drawings, which formapart of this specification, Figure 1 represents a side view of my invention; Fig. 2, a Vertical section of the interchangeable transxnitter and receiver on an enlarged scale, and Fig. 3 is a plan view thereof.

A represents a tube which may be of metal, paper, rubber,orothersuitable material adapted for the purpose and the conditions under which it is to be used. At each end of the tube is secu red an interchangeable transmitter and 1'eceiver,B,which is made in two parts, O and D, connected together by screW-threads at E with a packing interposed at a. Resonating-chambers F F' are formed in each section, (designated G and D, between which is secured a fixed diaphragm, G, perforated by a central aperture, c, and a series of apertures,d. Upon the outside of the diaphragm G is placed a movable diaphragm, H, which is secured at one point only. The fixed diaphragm forms a support for the movable diaphragm, and the perforations in the former direct the soundwaves coming from the tube upon the center of the latter, thus causing the free diaphragm to vibrate in either direction by direct impact of sound-Waves.

The part O of the transmitter and receiver is provided with an annular shoulder, b, between which and the fiXed diaphragm the free portion of the movable diaphragm vibratesv under'the pulsations of the sound-Waves transmitted through the tube A. An aperture, I, 8 5 directs the impulses of the voice upon the diaphragms. The diaphragrn H being fixed at one point in its circumference only, and having no obstructions resting upon its surfaces, is exceedingly Sensitive, and vibrates under go the slightest impact of sound-Waves directed against it from either side.

The diaphragms may be made of paper, hard rubber, mica, thin metal or other suitable material adapted for the purpose. The movable diaphragm is made very thin, and being free to vibrate at its periphery is exceedingly sensitive, and in practice has been found to transmit the most delicate sounds produced upon it and render themaudible at a distance through a tube provided with alike instrument at its opposite end.

The transmitter is provided with a tube, e, which passes over the tube A and secures the two together. w

Practice has demonstrated the fact that the instrument is equally as well adapted for a transmitter as a receiver. This enables me to dispense with the month-piece and transmitter used in the ordinary telephones, and provides a very simple, cheap, and durable instrument.

Another advantage in my device is due to the fact that in the use of the instrument the air eontained in the tube and put in motion by the vibrations or pulsations of the diaphragms is not permitted to strike the tympanum of the ear of the person receiving the message, which has a tendency to confuse and modify the tone of the speaker, and yet so arranged that through lack of rigidity of the diaphragm the most feeble sounds are reproduced, both as to quality and volume.

Having thus fully described my invention, what I claim is- 1. In apneumatic telephone,means for transmitting and reproducing articulate or other sounds, consisting of an interchangeable transmitter and receiver provided with a free or unobstructed diaphragm fixed at one point only, and Operating in either direction by the impact of sound-Waves, substantially as described.

2. Means for transmitting and reproducing articulate or other sounds, consisting of a tube containing free air, in combination with a free unobstructed diaphragm fixed at one point in its circumference only, and adapted to either transmit or receive said sounds, substantially as described.

3. Means for transmitting and reproducing articulate or other sounds, consisting of an interchangeable transmitter and receiver provided with a fixed perforated diaphragm, and a free vibrating diaphragm fixed at one point only, substantially as described.

' 4. In apneumatic telephone,means for transmitting and reproducing .articulate or other sounds, consisting of a resonating-chamber, and a free unobstructed diaphragm fixed at one point in its circumference only, and operating in either direction by impact of sound- Waves, substantially as described.

5. Means for transmitting and reproducing articulate or other sounds, consisting of a free unobstructed diaphragm fixed at one point only, in combination With two resonatingchambers, substantially as described'.

6. Means for transmitting and reproducing articulate or. other sounds, consisting of afixed perforated diaphragm and a free vibrating diaphragm fixed at one point only, in combination with a resonating-chamber, substantially as described.

7. Means for transmitting and reproducing articulate or other sounds, consisting of al fixedl perforated diaphragm and a free vibrating diaphragm fixed at one point only, interposed between two resonating chambers, substantially as described.

- 8. The combination of a tube or sound conveyer containing free air with two interchangeable transniitters and receivers, each provided with a free diaphragm fixed at one point only, and Operating in both directions by'impact of sound-Waves, substantially as described.

9. An interchangeable transmitter and receiver composed of two sections,one of which .is provided with an aperture and an annular shoulder, in combination with a fixed perforated diaphragm and 'a free vibrating diaphragm fixed at one point only, substantially as described. i

In testimony whereof I affix my signature in presence of twowitnesses.

.J AMES A. MALONEY.

Witnesses:

O. A. NEALE, o WM. E. DYRE. 

